It is known to provide utility machinery with a feeder mechanism fed with material gathered by gathering elements. The gathering elements may be configured to gather the material from an operating area somewhat wider than the machine and to move the gathered material to the feeder mechanism. They may form a two stage gathering process, which initially involves collecting in the material across the width of a window of operation and moving some material inwards towards an intake mouth or conveyor of the feeder mechanism, e.g. material collected in portions of the operating area that lie outboard of that intake mouth/conveyor. The feeder mechanism then conveys the gathered material into the machine for processing and/or redistribution.
Some known arrangements of this general type may be found on certain utility machinery used for agricultural harvesting, such as combine harvesters or forage harvesters. Many such machines are fitted with a header attachment that includes the gathering elements in the form of a primary crop gatherer, such as a pick-up drum, a reel or a crop cutter, and a secondary crop gatherer such as an auger. It is known to drive the primary and secondary crop gathering elements in common, so as to gather crop and to convey it to the feeder mechanism substantially continuously and at a synchronised rate. This is achieved using a drive band, such as a belt or chain drive, running between drive wheels associated with the gathering elements, e.g. pulleys, toothed wheels, sprockets or pinions as the case may be.
The secondary gathering element is generally rearward of the primary gathering element and for convenience is the driver. It is driven itself by a lower shaft of the feeder mechanism, which acts as the header drive shaft. In this manner, at least in some base models, the feeder mechanism and the header are driven substantially in unison.
It is not unknown for the feeder mechanism or one or the other gathering elements to become jammed, as may happen in the event of a slug of crop being drawn in which is too large to be processed. Such a situation might cause one or both of the gathering elements to stall partially or fully, which can mean a delay in harvesting while the jam is cleared. To try and reduce the inconvenience this might cause and to speed up clearance of such blockages, it is further known to provide the ability to drive the gathering elements in reverse, so as to aid removal or redistribution of the cause of the blockage. As drive to the header attachment and consequently its gathering elements is provided from a drive band of the feeder mechanism, header reversal is achieved by reversing the direction of travel of that drive band.
In U.S. Pat. No. 4,430,847 a crop feed mechanism is proposed in which, upon detection of a jammed condition in a crop conveyor or an auger, a user operates the feeder drive mechanism in reverse. The reversing arrangement includes a hydraulic motor adapted to drive the feed conveyor and auger in the opposite direction to that used for gathering crops. The feed reverse drive mechanism includes a sprocket secured for rotation with the upper feed drive shaft, a sprocket secured to an output of the hydraulic motor and an endless flexible drive chain tensioned by an idler sprocket whose mounting bolt may be selectively positioned vertically along a slot in an idler mounting bracket. The mechanism further includes a relief valve in the pump hydraulic circuit to prevent the delivery of excessive torque to the conveyors and auger during a feed reversing operation. In this prior art arrangement, an additional driveline is added to the machine in order to provide reversing of the feeder mechanism.
It is generally desirable in the art to develop systems which reduce one or more of the parts count, complexity and associated cost of providing, using and/or maintaining drive arrangements such as those used to reverse the direction of operation in a feeder mechanism of utility machinery.